1. Field of the Invention
The present invention relates to a snowshoe and, more specifically, to a frame structure of such a snowshoe.
2. Description of Background and Material Information
In a manner known in itself, snowshoes have a screen surrounded by a rigid frame whose closed contour defines the carrying surface, and a support piece which extends to the inside and on which the user's boot is attached. Normally, wooden snowshoe frames, possibly reinforced by a crosspiece, are closed by means of cords, straps, and/or assembly means connecting its ends after being shaped. For these snowshoes, and in order to allow the pivoting of the foot to ease walking, the support piece is connected to the flanks of the snowshoe frame and has a rotational axis extending transversely to the frame. Since the rigid frame has a closed contour and the support piece is connected transversely to its flanks, the frame cannot, by deforming itself, adapt to the layout of the terrain with respect to the natural transverse balance position of the user's foot, especially on sloped terrain.
Consequently and almost generally, it is the support piece which is provided with a possibility of transverse and vertical displacement allowing to at least partially redress the transverse balance position of the foot when the snowshoe is laterally inclined.
Such is the case, for example, of snowshoes whose screen and rotational axis of the support piece are constituted of hide cut up in cords. Indeed, because of the flexibility-suppleness of these cords, the user's foot can cause the boot to tilt laterally on the heaviest side with the support piece by deforming the cords.
This is also the case of the snowshoe described in U.S. Pat. No. 5,253,437, where the frame has a rigid tubular structure, defining a closed contour, with a support piece having transverse strips on which the boot is supported. In the case of the snowshoe taught by European Patent Application No. 0 613 703, the solution is different from the preceding examples in that the attachment of the boot is made on a support piece that has a second rotational axis extending longitudinally to the frame, i.e., oriented perpendicularly to the rotational axis allowing the pivoting of the foot in the walking direction.
In this construction, the support piece can tilt laterally, on the side where the load applied thereon by the foot is exerted, like a balance beam, consequently allowing to at least partially redress the transverse balance position of the foot in a manner comparable to the previously disclosed snowshoes.
The result of the aforementioned state of the art is that the structure with a closed contour frame requires providing a support piece for the boot that is relatively flexible due to the use of cords, despite the risks of rapid wear, or that is provided with a second rotational axis, despite the ensuing complexity of construction.
In summary, the frames of known snowshoes always remain fixed and nondeformable in the plane of the carrying surface that they define given their rigidity and closed contour, and it is the support piece that is fitted to allow correcting the lateral setting of the user's foot. This way of designing snowshoes, therefore, offers solutions that are more or less satisfying in providing a good support position for the foot on sloped terrain, but still presents the disadvantage of not allowing the frame to adapt to the layout of the terrain, which has a negative effect on gripping, especially when one walks on slopes and relatively hard snow.
Another disadvantage relates to manufacturing costs, since a closed contour frame structure requires implementing specific assembly means to guarantee that the frame will hold its shape, for example, strips, cords, welding, nut-screw systems, etc., on the one hand, and specific means for allowing the support piece to at least partially redress the natural transverse balance position of the foot when the snowshoe is placed on a slope, on the other hand.